Many underfloor extendible ramps are known, including those driven by motors and including those ramps fulcrummed intermediate their ends so that the inner ends of the ramps can be tilted up to be flush with the floor above them. Ramps also are known to have motor means for tilting these ramps. However, no reference was found combining all of these features, nor in the specific way and by the specific means invented by applicants. Furthermore, no such ramps were found with parallel side barriers which automatically folded when the ramp was retracted.